A prior art fuel system for an engine-driven vehicle having electronic fuel injection (EFI) includes a fuel tank, a fuel pump and a fuel line that delivers fuel from the pump to fuel injectors disposed in a fuel rail. The fuel pump of the prior art EFI fuel system comprises an electrically driven motor using brushes for motor commutation. High flow rate fuel pumps require high amounts of electrical power. When used in typical fuel systems (where the pump operates at constant full power) brushed pumps can create excessive heat. This build up of heat in the fuel system can lead to cavitation failures and low efficiency engine demand. High current draw during idle and low cruise put extra strain on the vehicle charging system as well. To address these problems, speed controllers are available to reduce the speed of the pump during low engine demand operating conditions. These controllers typically comprise electronic control modules connected to sensors disposed in the fuel system. The controllers also are electrically connected to the fuel pump and operate to alter pump speed by outputting a pulse width modulated power supply signal. This process reduces the incoming voltage to the fuel pump by limiting current draw. The use of such pump control systems has limited efficiency due to the reliance on fuel pumps employing motor brushes. In addition, such electronic control devices can be expensive and hence are not universally employed.
It is also known in the prior art to use a fuel pump comprising a brushless motor. Such motors use a rotor cylindrically arranged within a stator assembly. Such brushless motors include hall effect switches for motor commutation and mechanically transmit power to an impeller having “roller” or “pin” shaped vanes. The impeller and motor of this pump are axially aligned in the direction of fuel flow. The prior art brushless motor however has certain drawbacks including over-compression or over-expansion of fuel while coursing through the pump and a limited ability to control the pump.